1. Field of the Invention
This invention relates generally to key duplicating processes, and more particularly is directed to a method for fabricating duplicate keys without a master key, and to a method for such fabrication that is compatible with automatic key making such that special key blanks and trained personnel are not necessary to the key making process.
2. Description of Related Art
The following art defines the present state of this field:
U.S. Pat. No. 3,796,130 (Gartner) describes an unattended semi-automatic, coin operated duplicate key vending machine for use by members of the general public, the machine having a supply of key blade blanks with different cross sectional shapes in storage. A customer may quickly select the correct blank by placing his key into one of a plurality of slots or selector openings. Each of the slots is adapted to receive a key blade of a different shape which cross section corresponds to the shape of one of the blanks in storage.
U.S. Pat. No. 4,062,261 (Stahl) describes a key cutting apparatus for cutting a series of longitudinally spaced notches in the blade of a key blank according to specifications set forth in key manufacturers"" codebooks. The apparatus includes a cutter mounted on a base, and a carriage assembly movably mounted on the base for controllable movement toward and away from the cutter. The carriage assembly includes a sub-carriage adapted for controllable independent movement in a direction perpendicular to the carriage assembly movement.
U.S. Pat. No. 4,117,763 (Uyeda) describes a method and apparatus for decoding and duplicating a key wherein the notches in the shank of the key are coded to a predetermined coded depth and spacing. An index card having a sequential index thereon corresponding to the predetermined coded depth is inserted into a housing and the key to be duplicated is inserted into, a slot in the housing where it engages an indexing member which enters one of the notches on the key and indicates on the card the coded depth of that notch.
U.S. Pat. No. 4,143,582 (Heimann) describes a small and simply operated recording apparatus employing an elastic pressure element that is utilized to make a three dimensional recording in thin metallic foil from each of the two sides of a primary key from which a secondary key is to be manufactured, the recordings placed in an interpreting apparatus, which may be located remotely from the recording apparatus, which permits extraction of precise three dimensional data stored in the recordings whereafter the extracted data is utilized in a key cutting apparatus to produce a secondary key, in all comprising a key making system.
U.S. Pat. No. 4,251,173 (Saucedo) describes a key cutter that includes a machine for cutting keys for most pin tumbler or disc tumbler locks. The machine is not a duplicator but is a machine for cutting keys by the code or number. The machine includes base, turret assembly, and an electric motor for operating or driving a cutting wheel.
U.S. Pat. No. 4,526,498 (Fieldhouse) describes a key forming machine that includes a machine frame, key cutting means mounted on the machine frame and operable to cut bittings at preselected locations and depths into a key blank to form a key, and a carriage assembly adapted to carry a key blank and mounted on the machine frame for movement for presentation of the key blank to the key cutting means. First and second indexing mechanisms are mounted on the machine frame and are operable to move the carriage assembly, for presentation of a carried key blank to the key cutting means, to indexed positions respectively corresponding to preselected biting locations and bitting depths.
U.S. Pat. No. 4,657,448 (Alexander) describes a pantograph angular bitted key cutting machine which facilitates the replication of angular bitted keys, commonly known as Medecod keys by automatically replicating the position, depth and angularity of each tooth. Accurate angularity, the most difficult of the variables to replicate, is assured by ensuring that the center of rotation of the angular tooth wall is perpendicular to the radius of the cutting head. Two major embodiments are provided. In the first, the cutting head and the guide that aligns with the original key are fixed in the same line. In the second embodiment the guide and the original key are placed directly behind the cutting head and the blank duplicate key.
U.S. Pat. No. 4,780,032 (Uyeda et al.) describes a key duplicating apparatus, which includes a base and platform supporting a reciprocating carriage assembly and a pivotally mounted housing. The carriage assembly has a key securement means which secures a blank key and a template key in alignment for positioning, respectively, with a notch cutting means and a notch depth indicating means, so that a template key may be duplicated by cutting notches of a predetermined depth and position into the shank portion of the blank key.
U.S. Pat. No. 5,042,330 (Lo) describes a key manufacturing method, which includes a first procedure to produce key bodies through material shape molding, side-edge cutting process, thickness, curvature and length milling process, bitting forming process, and numbering and classification process according to shape of bitting; a second procedure to produce sheaths through copper rod planing process, conical front end milling process, groove lathing process and opposite inner wall trimming process; and a third procedure to fixedly fasten a key body in a sheath to form a unitary round key.
U.S. Pat. No. 5,128,531 (Fadel) describes an optical profile reader, particularly for key duplicating machines, incorporating a photoemitter on one side of the profile to be read, and a photodetector facing the photoemitter, but on the opposite side of the profile to be read. Stepper motors are included for causing the profile to be read to move orthogonal to the direction of a light beam striking the profile to be read. An electronic circuit controlled by the output signal of the photodetector is also provided. The electronic circuit uses a threshold discriminator set at a value between the values corresponding to the maximum and minimum illumination states of the photodetector. The threshold discrimination circuit also controls the operations of the stepper motors.
U.S. Pat. No. 3,826,555 (Matsumoto) describes a holography device which is comprised of a beam splitter arranged in the optical path of an incident beam from a beam source, and beam splitter splitting said incident beam into at least three beams. At least one transmitted beam and at least two reflected beams, said transmitted beam and at least one of said reflected beams being used as an illuminating beam for the object and the other reflected beam being used as a reference beam, said object transferring its illuminating beam into a signal beam.
Conventional key duplicating machines are typically manually operated wherein a skilled technician is needed to set-up, operate, and guide a holding device to produce a working product. Such duplicating machines are designed so that the technician must have a prior knowledge, skill, and ability to select a specific key blank or stock as to match the master or original key to be-duplicated or copied.
Such devices (machines) are produced with specific instructions as to the degree of capabilities for its original intent. Some machines are solely designed to cut and duplicate only certain manufacturers"" keys, as for example: Medeco, Abloy, Assa, Schlage Primus, with side milled, dimpled and grooved keys. Others are designed to only cut simple common keys such as Kwikset, Weslock, and Weiser generally used in household locks.
Such machines are temperamental requiring frequent adjustments and alignments caused by wear and tear from motor driven belts, worn key cutting blades, and key alignment guides, gauges and stops.
Also, the user must correctly and consistently install and align the original or master key and key blank in the holding apparatus of the key machine to insure correct calibration of depth and spacing when cutting proceeds. Not tightening the key holding apparatus properly also becomes a serious problem, since the key may move or be ejected by the cutting blade when contact is made and thereby cause a failure to duplicate.
Another problem occurs when the xe2x80x9cstopxe2x80x9d on the original key has been worn off, and there is no consistent way to align both the original key and the key blank on the holding apparatus of the key machine. Improper spacing of the cuts will occur causing improper function of the cut key.
Some prior key machines hold the original key to be cut by the actual grooves in the key blank. Special clamps and holders must be purchased for this procedure to be possible, causing a new set-up of th key machine to be necessary. Again, alignment and adjustments are required.
Fadel teaches an optical profile reader for a key-duplicating machine. Such a device, while well suited for automatically cutting a duplicate key without the use of a master in contact with the feeler, still requires the use of a key blank or stock supplied by the manufacturer. Thus reverting back to the problems of alignment, calibrations, human errors, spacing, worn key cutting blades, worn drive (motor) belts, lubrication of dovetail slides, set-up of key blanks in clamp holding apparatus, light infractions that may upset the balance of the optical reader giving false readings, and worn alignment stops on the original key, which would misalign the key blank to be duplicated. Some original keys, such as Ford vehicle keys, have no xe2x80x9cstopsxe2x80x9d for alignment, which presents an initial alignment problem.
The prior art teaches methods for duplicating keys of all types including common flat blade keys as well as barrel keys comprising a hollow cylindrical shaft, bit keys (skeleton keys) and many new style designs having complex cross-sections such as modified tubular keys. However, key duplicating is still dominated by slow and skilled labor factors except for the most common key types which are at least semiautomated. Yet key configuration and size types have grown to now include a truly extensive number making it nearly impossible, to provide an inexpensive and quick solution for a full range key replication operation. The primary factors that drive both price and availability in this field are cost of inventory of a very large number of key blank types, and training of personnel in the art of blank selection and key duplication and finishing.
Simple solutions to a wider range of key cutting and less expensive key replication such as provided by Fadel with his two dimensional photodetection approach, and to automation, such as taught by Gartner with his key duplicating and vending machine suffer from two problems. First, these approaches are not universal because they only accommodate a limited number of key types in practice since standard key cutting methods are employed. Second, these methods require a master key to be used as a template in making a duplicate key.
Accordingly, there is a need for a novel key making process which duplicates, copies, clones, or makes from scratch, an exact required key conformation and which is less complex and more trouble free than present key manufacturing and duplication processes. Further, such a novel process could be made to store information, codes, key cuts, manufacturer data and specifications, and used at any time when needed. Duplicate keys could be made from data stored in memory to cut a first or duplicate key or even alter its specifications if desired. The present invention fulfills these needs and provides further related advantages.
The main objective of the present invention is to provide a key-manufacturing process that is easily automated so as to require little operational skill or knowledge, and requires no set-up and no key blanks.
Another objective of the present invention is to provide a method of making a duplicate key from a stored electronic representation of the contour of a master key.
Yet another objective is to provide such a method capable of producing a duplicate key when the master is physically unavailable.
A further objective is to provide a method which may be reduced to an inexpensive and fully automatic, rapid key replication procedure so as to enable low cost key replication without the necessity for a locksmith or other duplication machine operating personnel.
Still a further objective is to provide a process capable of using a database and a CAD-CAM or CIM system for manufacturing original keys by code.
The foregoing objectives are achieved by the present invention which provides a method for fabricating a duplicate key from a stored electrical representation of the three-dimensional contour of a master key, real or virtual. The inventive process uses an approach that is able to capture, as electronic signals, the conformation of any size and shape of all key types. Therefore when keys are initially produced, all that is necessary for their later replication is to download a copy of the electronic signals of the keys rather than the master key itself, which of course, may be lost or unavailable. The method further includes a means by which the electronic signals are used to make-up a duplicate key from a generalized raw material rather than from a key blank. This is accomplished through the use of three-dimensional scanners, CAD-CAM techniques, and a manufacturing device. This approach avoids the current requirement of a large inventory of key blanks, and the necessity of specialized operators, and overcomes the time and expense involved when a master key is lost.
The method for making a duplicate key from profile data associated with a master key generally comprises the following steps: first, capturing an exterior surface conformation of a master key as an electrical signal representation in three-dimensions; second, storing the electrical signal representation as a permanent data image; and third directing a key manufacturing device to construct a duplicate key from non-traditional key blank raw material using the stored electrical signal representation.
The method for capturing the exterior surface conformation of the master key may comprise an optical scanning method using a holographic camera, or a mechanical probe. The resulting electrical signal representation may be assigned a unique code and stored on a database for later retrieval.
Typically, a three-dimensional modeling device is utilized to construct the duplicate key. Such three-dimensional modeling devices can include a fused deposition modeling device which uses thermoplastic filament to construct the duplicate key or a stereolithographic device using stereolithographic fluid. Alternatively, a milling device or high energy beam can be used to construct a duplicate key from a metal slug. Further, an injection molder device using high density molding resin may be utilized to construct the duplicate key.
Other features and advantages of the present invention will become apparent from the following more detailed description, which illustrate, by way of example, the principles of the invention.